This application is for funds to enable the principal investigator to complete a monograph on "Steroid-Protein Interactions". This book will be a continuation volume to a previous monograph of the same title which appeared in 1971. It will not repeat any material discussed in the first monograph, but will present a comprehensive and critical review of new results achieved since 1970 in many laboratories including that of the applicant. The emphasis will be on steroid interactions with serum proteins, but interactions with other steroid-binding proteins (tissue proteins, enzymes, immunoglobulins, intracellular receptors) will be included to the extent as the results are sufficiently established from a biomedical and physiocochemical viewpoint.